Unit 7 homework PDF

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Unit 7 homework...

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QMB 6603 Instructor: Dr. Jim Han Unit 7 Homework p.520 #1 a.

Chart Title 16 14 12 10 8 6 4 2 0 0.5

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1.5

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b. Scatter diagram in part a says that x and y has positive relationship. c.

Chart Title 16 14 12 10 8 6 4 2 0 0.5

d.

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Chart Title 16 14 f(x) = 2.6 x + 0.2

12 10 8 6 4 2 0 0.5

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y = 2.6x + 0.2 e. y = 2.6x + 0.2 y = 2.6*4 + 0.2 y = 10.4 + 0.2 y = 10.6 p.521 #4 a.

%Management 70 60

% Management

50 40 30 20 10 0 40

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50

55

% Working

60

65

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b. The scatter diagram indicates a positive relationship between %working and %Management. c.

%Management 70 60

% Management

50 40 30 20 10 0 40

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60

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% Working

d.

%Management 70 60 f(x) = 1.3 x − 35

% Management

50 40 30 20 10 0 40

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% Working

60

y = 1.3x – 35 e. y = 1.3*60 – 35 y = 78 – 35 y = 43 p.526 #14 a.

Chart Title 84 82 80 78 76 74 72 70 68 66 65

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b. Positive relationship c. xi Thinkpad X200 VGN Z598U U6V Elitebook 2530P X360 Thinkpad X300 Ideapad U110 Micro Express JFT2500 Toughbook W7 HP Voodoo Envy133 Mean Total

yi 87 85 80 75 80 76 81 73 79 68 78.4

83 82 81 78 78 78 77 75 73 72 77.7

(xi-xmean)*(yi- (xixi - xmean yi - ymean ymean) xmean)^2 8.6 5.3 45.58 73.96 6.6 4.3 28.38 43.56 1.6 3.3 5.28 2.56 -3.4 0.3 -1.02 11.56 1.6 0.3 0.48 2.56 -2.4 0.3 -0.72 5.76 2.6 -0.7 -1.82 6.76 -5.4 -2.7 14.58 29.16 0.6 -4.7 -2.82 0.36 -10.4 -5.7 59.28 108.16 147.2

284.4

B1 B0 B0 B0

= = = =

147.2/284.4 = 0.57 ymean – b1*xmean 77.7 – 0.57*78.4 33

Equation: Y = 33 + 0.57x d. y = 33 + 0.57*70 y = 33 + 39.9 y = 72.9

p.532 #15 xi yi 1 2 3 4 5

xi

yi 1 2 3 4 5

Mean

y=0.2+2.6x 3 7 5 11 14

Deviation 3 7 5 11 14 8 SST

2.8 5.4 8 10.6 13.2

yi - ypredicted yi - ypredicted square 0.2 0.04 1.6 2.56 -3 9 0.4 0.16 0.8 0.64 SSE 12.4 Squared Deviation

-5 -1 -3 3 6

25 1 9 9 36 80

SSR = SST – SSE = 80 – 12.4 = 67.6 b. r^2 = SSR/SST = 67.6/80 = 84.5 => 84.5% of the variability in y can be explained by the linear relationship between the size of x and y.

p.532 #18 y = monthly salaries x = students who obtained a bachelor’s degree in BA

equation = y = 1790.5 + 581.1x y = 1790.5 + xi yi 581.1x yi - ypredicted yi - ypredicted square 2.6 3300 3301.36 -1.36 1.8496 3.4 3600 3766.24 -166.24 27635.7376 3.6 4000 3882.46 117.54 13815.6516 3.2 3500 3650.02 -150.02 22506.0004 3 3900 3533.8 366.2 134102.44 2.9 3600 3475.69 124.31 15452.9761 SSE 213514.6553

xi

yi 2.6 3.4 3.6 3.2 3

Mean

Deviation 3300 3600 4000 3500 3900 3660 SST

-360 -60 340 -160 240

Squared Deviation 129600 3600 115600 25600 57600 332000

SSR = SST – SSE = 332000 – 213514.7 = 118485.3 b. r^2 = SSR/SST = 118485/332000 = 35.7% 35.7% of the variability in monthly salaries can be explained by the linear relationship between the size of monthly salaries and GPA.

p.534 #22 xi

yi 3700 2500

Squared Deviation

Deviation 87 84

13 10

169 100

2800 1900 1000 800 1700 600 Mean

82 74 73 69 68 55 74 SST

8 0 -1 -5 -6 -19

SSR = SST – SSE SSR = 756 – 173.88 = 582.12 R^2 = SSR/SST = 582.12/756 = 77%

64 0 1 25 36 361 756...